In retail environments, out of stock detection, low stock detection, price label verification, plug detection (SKU (stock keeping unit) in the wrong location) and planogram compliance (e.g. determining whether products on a “module” of shelving conform to specified plan), are common problems that are usually solved by dispatching human associates to physically check for issues in the store. For example, the associates visually assess the shelves for issues, and scan the “Shelf Label” barcodes to fetch relevant information regarding the product which is supposed to be on the shelf from the retailer's SKU database. However, such methods are both extremely labor intensive and error prone. Furthermore, the data generated by the human associates is often not in a machine-readable form and requires manual processing before the problem can be resolved, leading to delays in the resolution of the issues detected. This results in replacement stock not making it back onto the shelves in a timely manner, leading to lost sales and dissatisfied customers. While multiple lidar (Light Detection and Ranging) sensors on a mobile automation apparatus can be used to scan the shelves, such multiple lidar sensors are prone to their own issues. For example, the multiple lidar sensors will generally scan in a vertical direction, so depending on the speed of the mobile automation apparatus, gaps between stock items may not be detected. Furthermore, the multiple lidar sensors are generally arranged vertically on the mobile automation apparatus to maximize their vertical coverage of the shelves. While this minimizes the effect of objects blocking various lidar sensors' individual lines of sight, the shadows differ from lidar sensor to lidar sensor which makes combining the lidar sensor data challenging.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.